1. Field
The present disclosure generally relates to tooling used to fabricate parts, especially those made of composites, and deals more particularly with a lightweight flexible mandrel that conforms to local contours of a part.
2. Background
Mandrels may be used to layup, compress and/or cure a variety of parts that may possess one or more curves, contours or surface features to which the mandrel must conform. For example, in the aircraft industry, stringers used in the fuselage or wings may be required to conform to composite skins that may be contoured and/or have surface features such as localized ply pad-ups or drop-offs.
In the past, mandrels have been formed from flexible composites that allow the mandrel surface conform to part contours. However composite mandrels are subject to damage during handling and may have a limited lifespan due to tool surface wear in higher production run applications. Metal type mandrels can be fabricated with geometries necessary to match part contours, however this type of tooling is relatively expensive to produce. In addition, metal mandrels having the necessary rigidity are relatively heavy and may require the use of an overhead crane or special equipment for handling them.
Accordingly, there is a need for a lightweight, flexible mandrel that readily conforms to local part contours and which may be easily handled without the need for cranes or special equipment. There is also a need for a lightweight flexible mandrel that is easily fabricated at low cost, is durable, and produces smooth part surface finishes.